WHAT: A protein known to promote allergic diseases in people helps the body defend against Staphylococcus aureus, a leading cause of bacterial skin infections in the United States, according to a study appearing in the November 18 issue of Science Immunology.

The study authors from the National Heart, Lung, and Blood Institute (NHLBI) say the finding offers insights that could be used to help improve treatments for staph-related infections, including the potentially deadly methicillin-resistant Staphylococcus aureus, commonly known as MRSA.

The researchers studied the role of a cytokine – a protein involved in cell signaling – called thymic stromal lymphopoeitin, or TSLP. The cytokine plays an active role in allergic diseases, such as asthma, promoting an increased number of T helper 2 cells that can have negative effects.

However, scientists found that increasing the amount of TSLP also can help activate neutrophils, a type of white blood cell that aids in warding off infections such as MRSA. Neutrophils trigger the body’s defenses, in part by creating bacteria-fighting phagocytes and other mechanisms.

Staphylococcus aureus infections prompt millions of emergency room and outpatient visits annually. While these infections once were most common in hospital settings, they increasingly are appearing in the community. MRSA infections, in particular, can lead to deadly consequences, such as pneumonia, sepsis and meningitis.

Researchers say their study, which examined skin infection in mice as well as human and mouse blood samples, found that TSLP plays a role in triggering the immune system to reduce the amount of bacteria in Staph infections. TSLP acted directly on neutrophils, and the authors showed the mechanism for the effect of TSLP. The findings come at a time when more antibiotic-resistant Staph infections are being reported, according to the researchers, and the insights learned have potential therapeutic implications for control of MRSA infection.

WHO: Warren Leonard, M.D., and Erin West, Ph.D., Laboratory of Molecular Immunology, NHLBI, NIH, are available to comment on the findings and implications of this research.

Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at http://www.nhlbi.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.